Splice box for a power distribution system

ABSTRACT

A splice box or coupler for a power distribution system of the type providing a substantially continuous convenience outlet enabling electrical plugs to be connected thereto at substantially any selected location therealong. The system includes one or more track components that provide such convenience outlet, and each such track component is equipped with a conductor assembly having a plurality of spaced-apart conductors. The splice box or coupler is connectable with such track component at an end thereof, and may be used either to join successive track components or to attach an end block or junction box thereto at which the conductors of the distribution system are connected with power supply lines. The splice box, for the purpose of establishing connection thereof with a track component, has a housing portion insertable into the end of a track component, and it is equipped with a plurality of contacts movable into engagement with the respective conductors of such track component when assembled therewith, and which contacts are selectively manipulatable to establish either a two-conductor single electric circuit or a three-conductor double electric circuit.

United States Patent [72] lnventors Larry L. Routh Castro Valley; JamesContratto, Livermore, both of, Calif. [21] Appl. No. 780,840 [22] FiledDec. 3, 1968 [45] Patented Sept. 14, 1971 [73] Assignee U.S. Industries,Inc.

New York, N.Y.

[54] SPLICE BOX FOR A POWER DISTRIBUTION l/1967 Hermann et a1 339/21 XABSTRACT: A splice box or coupler for a power distribution system of thetype providing a substantially continuous convenience outlet enablingelectrical plugs to be connected thereto at substantially any selectedlocation therealong. The system includes one or more track componentsthat provide such convenience outlet, and each such track component isequipped with a conductor assembly having a plurality of spaced-apartconductors. The splice box or coupler is connectable with such trackcomponent at an end thereof, and may be used either to join successivetrack components or to attach an end biock or junction box thereto atwhich the condoctors of the distribution system are connected with powersupply lines. The splice box, for the purpose of establishing connectionthereof with a track component, has a housing portion insertable intothe end of a track component, and it is equipped with a plurality ofcontacts movable into engagement with the respective conductors of suchtrack component when assembled therewith, and which contacts areselectively manipulatable to establish either a two-conductor singleelectric circuit or a three-conductor double electric circuit.

PATENTEU SEP1 4 ml SHEET 1 [IF 2 24a h" 476 I 54 25a L4 4.7-1,

INVENTOR. LARRY L. ROUTH BY JAMES CONTRATTO Attoraeqs SPLICE BOX FOR APOWER DISTRIBUTION SYSTEM This invention relates to a power distributionsystem and, more particularly, to a splice box or coupler for a powerdistribution system having elongated rack components provided withsubstantially continuous receptacles or convenience outlets therealongadapted to have plugs connected thereto at substantially any selectedlocation along the length thereof.

As explained in the copending patent application of Larry L. Routhentitled Power Distribution System," Ser. No. 695,655, filed Jan. 4,I968, the location of convenience outlets, junction boxes, and otherfixed points of connection within an electric power distribution systemis most often a compromise with the various locations being selected onthe basis of custom or in anticipation of the use expected for thebuilding space containing the distribution system. This is particularlyunsatisfactory especially in commercial and industrial buildings sincethe use of any particular space therein is not necessarily static, andany change in use may require relocation of the various outlets andother points of connection. In this respect, the divider walls orpartitions in such buildings may be changed bodily, and modern buildingsare designed so as to afford ready change of such dividing walls fromone location to another so as to provide considerable versatility in theuse of the building space. In view of this, power distribution systemshave been proposed heretofore which are intended to afford a degree offlexibility as respects the location at which lights and otherelectrically operated devices may be connected thereto, and one suchsystem is disclosed in the aforesaid US. Pat. application, Ser. No.695,655.

A difficulty with existing power systems of this type is thatinterconnection of the receptacle-equipped track components thereof iseffected by splice boxes requiring special connector arrangements at theends of the track components, and as a consequence, it is very difficultto interconnect successive track components unless they are of standardlengths equipped with such special arrangements at the ends thereof atthe time of their manufacture. Clearly, this requirement imposeslimitations on the use of these systems since in those instances inwhich standard lengths can not be employed, it has usually beennecessary to have special or custom lengths made to order. In view ofthis, a general object of the present invention is to provide animproved power distribution system of the type affording substantiallyinfinite selection of the locations along the lengths thereof at whichlights and other electrically operated devices can be connected thereto,and which improved system has track components and splice boxes enablingquick and easy interconnection therebetween without the requirement forspecial connection arrangements at the ends of the track components,thereby enabling the same to be cut at the site of their installation toany requisite lengths.

More particular objects, among others, are to provide an improved powerdistribution system of the character described in which each trackcomponent can be used in either a two-conductor single electric circuitor three-conductor double electric circuit without change, and in whicheach splice box or coupler is similarly equipped for use in either suchcircuit and is connectable quickly and easily with such track componentso as to condition the same selectively for the desired two-conductor orthree-conductor circuit; and to provide a splice box having a housingequipped with a forwardly extending section adapted to be inserted intoa chamber provided along the receptacleequipped track component, andwhich splice box is further provided with guide structure cooperativewith such track component to establish a predetermined positionalrelationship therebetween, the splice box having a plurality of contactsnormally disposed in an inner retracted position during such insertionof the housing secton into the track components and selectivelydisplaceable outwardly through the manipulation of selector structure toestablish connection of the contacts with the conductors of the trackcomponent either in a two-conductor or -three-conductor circuitconfiguration. Additional objects and advantages of the invention,especially as concerns particular features and characteristics thereof,will become apparent as the specification develops.

A power distribution system embodying the present invention may includea plurality of elongated, longitudinally extending track componentsconnected one with another in a succession thereof, and such trackcomponents may include a splice box and a receptacle-equipped trackcomponent defining a longitudinally extending convenience outlettherealong. Each of the track components is relatively rigid and isintended to be supported along a ceiling or other building wall and, inmany cases, is either partially or completely embedded therein. Eachreceptacle-equipped track component is adapted to have male plugsconnected at any suitable location along the conveience outlet thereof,and cooperative polarization means may be provided by the trackcomponent and by such plug to permit connection thereof in only onerelative orientation. Each splice box is connectable with a trackcomponent at an end thereof, and in interconnecting two successive trackcomponents a pair of reversely oriented splice boxes may be used inrespective association with such components;

and such splice box may also be used at an end of a track component toconnect the conductors thereof with a junction or end box within whichconnection is made to other conductors such as power supply lines.

An embodiment of the invention is illustrated in the accompanyingdrawings, in which:

FIG. 1 is a broken perspective view illustrating in spacedapart relationcertain components of a power distribution system embodying the presentinvention;

FIG. 2 is an enlarged, perspective view illustrating in spaced-apartrelation the various elements of a splice box forming one of thecomponents of such power distribution system;

FIG. 3 is a transverse sectional view, taken along the line 33 of FIG.1, of a receptacle-equipped track component forming a part of the powerdistribution system;

FIG. 4 is a broken side view in elevation of the components shown inFIG. 1 but in their interconnected state, one of the splice boxesthereof being for the most part shown in longitudinal section;

FIG. 5 is a broken top plan view of the interconnected com ponents shownin FIG. 4 with portions of the same splice box being illustrated incross section and in a neutral condition in which the contacts thereofare not connected with the conductors of the associatedreceptacle-equipped track component;

FIG. 6 is a top plan view similar to that of FIG. 5 but showing thesplice box conditioned for a three-conductor double electric circuit;and

FIG. 7 is a broken perspective view showing the splice box inassociation with an end box or connector block of such powerdistribution system.

The power distribution system illustrated in FIG. I can be usedselectively as a two-conductor single electric circuit of athree-conductor double electric circuit, and it includes a plurality ofinterconnected track components respectively denoted with the numerals10, II, I2 and I3. The track components l0 and I3 are substantiallyidentical in construction and function, and they are eachreceptacle-equipped components adapted to have one or more plugs (notshown) connected therewith at various locations therealong. The trackcomponents 11 and 12 are each splice boxes and as shown each is used asa coupler or joiner box by means of which a plurality ofreceptacle-equipped track components 10 and I3 of any convenient ornecessary length may be connected one with another.

In the usual case a splice box is also provided at least at one end of arun of track components so that the conductors thereof can be connectedconveniently to power supply lines. FIG. 7 illustrates such anarrangement adjacent the outer end of the track components which isequipped thereat with a splice box 14 having an end or connector box 15arranged therewith and within which the conductors of the powerdistribution system are connected with the power supply lines.

The track components 10 and 13 may be substantially the same as thosedisclosed in the aforementioned copending patent application of Larry L.Routh, Ser. No. 695,655, filed Jan. 4, 1968, and are adapted for usewith a male plug or adapter of the type shown and described in suchapplication and which adapter can be releasably secured to the trackcomponents at selected locations therealong. Such plugs or adapters andthe receptacle-equipped track components are polarized so as to causeeach plug to have a predetermined orientation with respect to anassociated track component, thereby causing particular polarities areobserved in interconnecting the same. Apart from such polarizationmeans, the receptacle-equipped track components are generallysymmetrical about a vertical centerline therethrough, and in view ofsuch general symmetry the same numerals are employed to identify theoppositely positioned counterpart elements except that the suffixes aand b are added for purposes of differentiation therebetween.

Accordingly, and referring to FIG. 3 in particular, the track component10 is seen to have a pair of longitudinally extending and transverselyspaced sidewalls 16a and 16b formed integrally with a longitudinallyextending web 17 that is transversely disposed and projects between thesidewalls intermediate the top and bottom thereof. Adjacent their upperends, the sidewalls 16 are turned inwardly to define flanges 18a and 18bthat in certain environments may receive a cover (not shown) thereonwhich together with the web 17 and spaced sidewalls l6 define alongitudinally extending chamber or wireway 19 in which insulated wiresor other conductors may be carried from one location to another, shouldthis be desired.

Exteriorly the sidewalls 16 may be provided with polarization means (notshown) to enforce a predetermined orientation onto a succession of trackcomponents interconnected one with another, as explained in theaforementioned copending patent application. The sidewalls 16 also maybe provided with outwardly extending flanges (not shown) useful incompletely or partially recessing the track components in a ceiling orother building wall-which flanges and their use are also disclosed insuch copending patent application. As respects the present invention,neither such polarization features nor mounting arrangement arepertinent and, therefore, necessitate no further discussion.

The track component 10 is provided with a chamber or receptacle 20 inunderlying relation with the web 17, and such receptacle defines alongitudinally extending convenience outlet adapted to receive one ormore of the aforementioned plugs or adapters. The elongated receptacle20 adjacent its upper end is provided with a longitudinally extendingcompartment 2] having a conductor assembly 22 mounted therein. Theconductor assembly 22 includes an elongated insulator or insulatedholder 23 turned inwardly upon itself along the longitudinal edgesthereof to form longitudinally extending slots in which are mountedconductors 24a and 24b. The slots confine the conductors 24 therewithinand are provided with restricted mouths adapted to pass therethrough thecontacts of such a plug or adapter. The insulator 23 is sufficientlyrigid to be substantially self-sustaining so as to maintain theconductors 24 in the spaced-apart relation shown and to confine the samewithin the slots therefor. The conductors 24 may be conventional copperwires (12 gauge, for example), and they may be constrained againstlongitudinal displacements with respect to the insulator 23 by collars(not shown) crimped about the conductors, all as explained in theaforementioned pending patent application.

The receptacle 20 defining the longitudinally extending convenienceoutlet is provided with polarizing means as mentioned hereinbefore,which includes a pair of transversely spaced and longitudinallyextending recesses 25a and 25b respectively disposed along the sidewalls16a and 16b adjacent the bottoms thereof. The recesses 25 are offsetwith respect to each other from top to bottom of the track component (asshown in FIG. 3) to efi'ect such polarization and, accordingly, thecorrespondingly polarized members of such plug or adapter are alignablerespectively only with the recess 25a or with the recess 25b as the casemay be. A third conductor 26 is carried by the insulator 23 for use whenit is desired to provide a three-conductor double electric circuit, andit will be observed that although the conductors 24 are disposed atsubstantially the same elevation in aligned parallelism, the adapter 26is offset upwardly therefrom and is at a slightly higher elevation thanthe conductor 24 and lies inwardly thereof.

As suggested heretofore, for the purpose of enabling thereceptacle-equipped track components to be readily accommodated by roomsand installations irrespective of the dimensional restrictions thereof,it is practicably necessary for such track components to be cut tolength at the site of their installation, thereby requiring splice boxesnd connector arrangements having no special structural characteristicsassociated with the track components which might be lost upon cuttingthe same to custom or special lengths. The splice boxes ll, 12 and 14are so connectable with the receptacle-equipped track components 10 and13 irrespective of their being cut to any particular lengths; and it maybe noted that the splice boxes ll, 12 and 14 are identical so that onlythe details of the box 11 will be set forththe primed form of the samenumerals used to identify the elements of the splice box 11 being usedwhere appropriate to identify the respectively corresponding elements ofthe splice box 12.

The splice box or coupler 11 is not intended to have plugs, adapters orother utilization devices connected therewith and, accordingly, does nothave an elongated receptacle for this purpose provided along theunderside thereof. Generally, the splice box is intended to establishconnection therethrough between successive track components or withconnector blocks or end boxes, and, therefore, includes a plurality ofcontacts to establish connection with respective conductors of the trackcomponent 10. In positive terms, the splice box ll is provided with apair of contacts 270 and 27b that respectively engage the conductors 24aand 24b of the track component 10, and with a third or additionalcontact 28 which is selectively engageable with the conductor 26 of suchtrack component and is used only when a three-conductor, double electriccircuit is intended.

The contacts 27 and 28 are mounted within a housing or casing 29 havinga forwardly extending section 30 insertable into the chamber 20 of thetrack component 10 (as shown in FIGS. 4, 5 and 6). The housing 29 isalso provided with a rear end portion 31 enlarged both transversely andvertically with respect to the section 30, and it is abuttable with theend of the track component 10 upon such insertion of the housing section30 thereinto, also, as shown in FIGS. 4 through 6. The housing isprovided therein with a contact compartment 32 and with a connectorcompartment generally denoted 33 and which is subdivided by walls 34aand 34b intoa central compartment section 35 defined between the walls34a and 34b and outer compartments sections 36a and 36b respectivelybordering the divider walls 340 and 34b (as shown best in FIGS. 5 and6).

The contacts 27a and 27b are respectively associated with the outercompartment sections 360 and 36b and the additional contact 28 with thecompartment section 35; and the divider walls 340 and 34b physically andelectrically separate the contacts 27 and 28 from each other within theconnector compartment 33. Within such compartment the contacts areconnected by suitable terminals 37a, 37b and 38, respectively, to leadwires 39a, 39b and 40; and as is most evident in FIGS. 1, 2 and 4, theentire connector compartment 33 is open at the rear end thereof toprovide access for connection of the lead wires 39 and 40 with therespective contacts 27 and 28 except along the upper end of thecompartment at which a downwardly extending rear wall section 41 isprovided. The wall section 41 is equipped centrally with a boss 42.having a threaded opening 43 therein which is used to connect a cover tothe housing, as will be described hereinafter.

Each of the contacts is elongated longitudinally with the contacts 27aand 27b being of the same length and disposed in transversely spaced,substantially parallel alignment, as is most evident perhaps in FIGS. 2and 3. Each of the contacts 27 extends forwardly from the connectorcompartment 33 and seats within a channel provided therefor that isdefined between the housing sidewall 44a and an upwardly extending boss45a adjacent thereto in the case of the contact 27a and between thehousing wall 44b and adjacent post 45b in the case of the contact 27b.The recesses respectively defined between the sidewalls 44 and posts 45confine the contacts 27 therein, and it may be observed that thecontacts are bent laterally adjacent the posts 45 and converge inwardlytherefrom for a portion of their length to space the forward endportions of the contacts from the housing walls 44, as shown in FIG. 5,when the splice box is not in use. At the time of such nonuse, theinclined edges 46a and 46b of the outwardly turned terminal ends 47a and47b of the contacts lie essentially within the transverse dimensions ofthe walls 44a and 44b. Thus, during insertion of the splice box 11 intothe chamber of the track component 10, the contacts 27 do not resist orotherwise inhibit such insertion.

Following such insertion, however, the contacts 27 are displacedoutwardly to cause such inclined edges 46 thereof to mechanically andelectrically engage the conductors 24 of the track component 10, andsuch outward displacements of the forward end portions of the contacts27 are effected by selector structure comprising an oblong or generallyelliptical cam 48 supported by the housing section 30 along the bottomwall 49 thereof for angular displacements between the neutral positionshown in FIG. 5 in which the greater axis of the ellipse is disposed ina longitudinal direction and an active position displaced therefrom by90 in which such greater axis of the ellipse is transversely oriented,as shown in FIG. 6. It should be noted that as concerns the two contacts27, the cam 48 may be angularly displaced in either direction (i.e.,clockwise or counterclockwise) from the position illustrated in FIG. 5for the purpose of displacing the contacts 27 outwardly to engage theterminal ends 47 thereof with the conductors 24.

In this respect, the forward end portions of the contacts 27 extendalong and in proximity with the bottom wall 49 of the housing section30, and such contacts are engaged by the cam 49 along the bottomthereof, wherefore the contacts 27 may be displaced independently of thecontact 28, as will be explained subsequently. It may also be observedthat the cam 48 has an end portion 50 extending downwardly through thebottom wall 49 of the housing section 30, and is provided with a slotfor receipt of a screwdriver by means of which the cam is rotated.

The third contact 28 is centrally disposed and lies intermediate thepaired contacts 27 and is somewhat shorter than such contacts in thelongitudinal direction. The contact 28 projects forwardly from theconnector compartment 33 through a slotted post 51 extending upwardlyfrom the bottom wall 49 of the casing section 30 and supportedintermediate the walls 44 thereof in a hollow collar 52 positioned alongthe bottom wall 49 and formed integrally therewith. As its forward end,the contact 28 projects upwardly (as shown at 53 in FIG. 2 and 4) and isturned laterally outwardly thereat to provide a terminal end portion 54having an inclined outer edge 55 engageable with the conductor 26 of thetrack component 10 whenever the contact 28 is displaced outwardly fromthe inner neutral position shown in FIG. 5 into the active outerposition illustrated in FIG. 6.

Ordinarily, the contact 28 has the position shown in FIG. 6 in which itextends generally along the longitudinal axis of the splice box 1!, andit is adapted to be engaged by an upwardly extending lip 56 of the cam48 upon displacement thereof through an angular distance approximating90 from the neutral position shown in FIG. 5. Whenever the cam 48 isangularly displaced in a counterclockwise direction, as viewed in FIG.5, into the position shown in FIG. 6, the upwardly extending lip 56 ofthe cam engages the contact 28 to displace it laterally, thereby causingthe inclined edge 55 of the terminal end 54 thereof to be pushed intoengagement with the conductor 26. At the same time, as explainedheretofore, the contacts 27 will be displaced into engagement with theconductors 24, whereupon a three-conductor double electric circuit willbe established-assuming that all three conductors of the track 10 aresuitably connected to supply lines.

However, if the cam 48 is displaced angularly in the 0pposite direction(or clockwise as viewed in FIG. 5) through a distance of the contacts 27will be displaced outwardly and into engagement with the conductors 24but the contact 28 will be displaced away from the conductor 26 (Le, asviewed in FIG. 5), whereupon the terminal end 54 thereof will becomeeven more remote from the conductor 26 of the track component 10, inwhich case a two-conductor single electric circuit will be established.Although in the ordinary instance the contacts 27 and 28 remain in theactive, extended position thereof when once displaced thereinto by theselector structure comprising the cam 48, the contacts have sufficientresilience to be self-biased toward their retracted inner positions, andmay be made of a material such as relatively hard brass which has suchinherent resilience.

The contacts 27 are isolated from each other adjacent the forward endsthereof by a generally U-shaped insulator 57 formed integrally with thehousing 29 and located within the contact compartment 32 thereof. Thecontacts 27 are further isolated adjacent the outwardly turned terminalends 47 thereof by a rib 58 (FIG. 2 in particular) that extends upwardlyfrom a cover 59 along the center thereof, and which cover is providedalong each side of the rib 58 with recesses 60a and 60b through whichthe end portions 47a and 47b of the respective contacts 270 and 27bextend. The cover 59 is adapted to seat upon the housing section 30 toclose the compartment 32 thereof, and it is secured in position bysuitable fasteners such as capscrews 61 and 62-the first of which isthreadedly receivable within an opening 63 provided therefor in theinsulator S7, and the second of which is receivable within theaforementioned threaded opening 43 in the boss 42 located adjacent therear end of the housing. Evidently then, the cover 59 has a steppedportion including a generally vertical wall 64 and a horizontalextension 65 projecting rearwardly therefrom which together close theforward and upper edges of the connector compartment 33. The cover 59 isalso provided with a transversely elongated opening 66 rearwardly of therib 58 and through which the upwardly extending portion 53 and terminalend 54 ofthe contact 28 extend.

Guide structure is provided for establishing a positive predeterminedposition of the splice box ll relative to the track component 10 uponinterconnection therewith and such guide structure takes the form of anextension 67 projecting forwardly from the vertical wall 64 inspaced-apart overlying relation with the cover 59. The extension 67 isprovided along each side thereof with depending walls 68a and 68b whichgives the guide structure an inverted, generally U-shaped configuration.The guide structure is slidably receivable in the wireway 119 of thetrack component 10, as shown best in FIG. 4, with the depending walls 68being dimensioned so as to substantially abut the facing inner surfacesof the walls 16 of the track component and so as to seat within thespaces defined between the flanges l8 and immediately the underlyingsurfaces of the web 17. The extension 67 has a transversely elongatedopening 69 formed therein which is used in structurally interconnectinga pair of splice boxes, and it is further provided with a threadedopening 70 also used in this same reference.

More particularly, when a pair of splice boxes I] and I2 are used tointerconnect successive track components I0 and 13, as shown in FIGS. Iand 4 through 6, the splice boxes are reversely oriented relative toeach other so that the rear sections 31 thereof abut. The splice boxesare constrained in such contiguous relation by a connector strap 71 thatbridges the two connector sections 31 and 31' and is provided withdownwardly offset fastener plates 72 and 73 which seat upon theextensions 67 and 67 of the splice boxes 11 and 12. The fastener plates72 and 73 are respectively provided with downwardly struck lugs 74 and75 dimensioned to seat, respectively, within the openings 69 and 69' ofthe extensions 67 and 67', as shown in FIG. 4. The fastener 71 issecured in such position by capscrews that extend through openings 76and 77 respectively provided therefor by the fastener plates 72 and 73and are threadedly received within the openings 70 and 70 provided bythe extensions 67 and 67 of the splice boxes. Thus, the connector strap71 fixedly interconnects the splice boxes 11 and 12.

As explained hereinbefore, a splice box may be used at an end of a trackcomponent for the purpose of connecting the same to a junction box orconnector block as shown in FIG. 7; and as respects the presentinvention, the end box 15 shown is adapted to be secured by capscrews orother suitable fasteners 78 to the splice box 14 and has an opening 79in a wall thereof through which lead wires (denoted in the aggregatewith the numeral'80) extend that are respectively connected with thevarious contacts of the splice box, The end box 15 is also provided withopenings in other walls thereof through which supply lines (not shown)enter the compartment 81 for respective connection with the lead wires80, and a cover plate may be secured to the box 15 to enclose thecompartment 81 thereof.

It is evident from the foregoing that the splice boxes are connectablewith a track component at an end thereof without the requirement forspecial structural provision thereat so that the track component can becut to any necessary or desirable length to accommodate the requirementsof a particular installation. Accordingly, it is only necessary to cutthe track component to the length desired insert the contact section 30of a splice box into the track component, and then rotate the selectorstructure comprising the cam 48 through an angular distance of 90,selectively, in one direction to establish a twoconductor singleelectric circuit or in the opposite direction to establish athree-conductor dual electric circuit. In joining two successivecomponents, a pair of splice boxes are employed, and they are oppositelyoriented as described, and may be interconnected by a strap 81 to unitethe same mechanically.

The housing 29, cover 59, and connector strap 71 may be formed of aninsulating material and may be fabricated of various materials havingthe characteristic such as one of the plastic materials, a polycarbonatefor example. The track component, except for the conductor assemblythereof, may be metal, extruded aluminum for example,

While in the foregoing specification an embodiment of the invention hasbeen set forth in considerable detail for purposes of making a completeddisclosure thereof, it will be apparent to those skilled in the art thatnumerous changes may be made in such details without departing from thespirit and principles of the invention.

We claim:

1. A splice box or the like for use in a power distribution systemhaving a track component provided with a longitudinally extendingchamber therealong equipped with a conductor assembly that includes aplurality of conductors insulating one from the others, comprising acasing having a section thereof insertable into such chamber, a pair ofcontacts mounted within said casing and movable with respect theretobetween inner retracted positions and outer extended positions forrespective engagement with such conductors following insertion of saidcasing section into such chamber, selector structure adjustably carriedby said casing for movement with respect thereto and being engageablewith said contacts to displace the same selectively from their retractedpositions into their extended positions, guide structure carried by saidcasing and cooperative with such track component to positively determinethe position of said casing with respect thereto upon insertion of saidcasing section thereinto and thereby enable interconnection of saidcontacts with the respective conductors of such track component byappropriate movement of said selector structure, and an additionalcontact mounted within said casing and being movable with respectthereto between an inner retracted position and an outer extendedposition for engagement with one such conductor following insertion ofsaid casing section into the chamber of such track component, saidselector structure being movable in one direction to effect displacementof said additional contact into the outer extended position thereofconcurrently with corresponding displacements of the aforesaid pair ofcontacts into their outer extended positions and being movable in anopposite direction to displace the aforesaid pair of contacts outwardlyinto their extended positions without so displacing said additionalcontact into its outer extended position, said casing being providedwith an end portion larger in at least one transverse dimension thansaid casing section and being abuttable with an end of such trackcomponent to limit the extent of insertion of said casing section intothe chamber thereof, said guide structure extending along said casingsection in spaced-apart overlying relation therewith for slidableinsertion into such track component.

2. The splice box of claim 1 in which each of said contacts is anelongated component having an end portion thereof extendinglongitudinally in substantially unsupported relation, and in which saidselector structure is engageable with the end portion of each contact todisplace the same laterally into its outer extended position and therebyeffect engagement thereof with a conductor of such track component.

3. The splice box of claim 2 in which said selector structure has anoffset portion engageable with said additional contact to displace thesame laterally into its outer extended position when said selectorstructure is moved in one direction and ineffective to displace it intosuch outer extended position when said selector structure is moved inthe opposite direction.

4. A splice box or the like for use in a power distribution systemhaving a track component provided with a longitudinally extendingchamber therealong equipped with a conductor assembly that includes aplurality of conductors insulating one from the others, comprising acasing having a section thereof insertable into such chamber, a pair ofcontacts mounted within said casing and movable with respect theretobetween inner retracted positions and outer extended positions forrespective engagement with such conductors following insertion of saidcasing section into such chamber, selector structure adjustably carriedby said casing for movement with respect thereto and being engageablewith said contacts to displace the same selectively from their retractedpositions into their extended positions, and guide structure carried bysaid casing and cooperative with such track component to positivelydetermine the position of said casing with respect thereto uponinsertion of said casing section thereinto and thereby enableinterconnection of said contacts with the respective conductors of suchtrack component by appropriate movcment of said selector structure, saidguide structure extending along said casing section in spaced-apartoverlying relation therewith for slidable insertion into such trackcomponent.

5. The splice box of claim 4 and further comprising an additionalcontact mounted within said casing and being movable with respectthereto between an inner retracted position and an outer extendedposition for engagement with one such conductor following insertion ofsaid casing section into the chamber of such track component, and inwhich said selector structure is movable in one direction to effectdisplacement of said additional contact into the outer extended positionthereof concurrently with corresponding displacements of the aforesaidpair of contacts into their outer extended positions and is movable inan opposite direction to displace the aforesaid pair of contactsoutwardly into their extended positions without so displacing saidadditional contact into its outer extended position.

6. A splice box or the like for use in a power distribution systemhaving a track component provided with a longitudinally extendingchamber therealong equipped with a conductor assembly that includes aplurality of conductors insulating one from the others, comprising acasing having a section thereof insertable into such chamber, a pair ofcontacts mounted within said casing and movable with respect theretobetween inner retracted positions and outer extended positions forrespective engagement with such conductors following insertion of saidcasing section into such chamber, selector structure adjustably carriedby said casing for movement with respect thereto and being engageablewith said contacts to displace the same selectively from their retractedpositions into their extended positions, guide structure carried by saidcasing and cooperative with such track component to positively determinethe position of said casing with respect thereto upon insertion of saidcasing section thereinto and thereby enable interconnection of saidcontacts with the respective conductors of such track component byappropriate movement of said selector structure, said casing having anend portion from which said section thereof extends and a connectorstrap for securing two such splice boxes in longitudinal dispositionwith said end portions thereof in substantial abutment and said casingsections projecting therefrom in opposite longitudinal directions, saidcasing being equipped with means for securing said connector strapthereto.

7. The splice box of claim 6 in which said casing is equipped with aremovable cover, and in which said securing means are provided thereby.

8. The splice box of claim 7 in which said casing and removable coverare provided with insulating barriers separating said contacts thereatto insulate the same from each other.

9. A splice box or the like for use in a power distribution systemhaving a track component provided with a longitudinally extendingchamber therealong equipped with a conductor assembly that includes aplurality of conductors insulating one from the others, comprising acasing having a section thereof insertable into such chamber, at leastthree contacts mounted within said casing and being movable with respectthereto between inner retracted positions and outer extended positionsfor respective engagement with such conductors following insertion ofsaid casing section into such chamber, three-position selector structurepivotally carried by said casing for selective displacements withrespect thereto in opposite angular directions from an intermediateneutral position into one or another of two active positions, saidselector structure upon displacement thereof in one angular directioninto one active position being engageable with a plurality of saidcontacts to move the same into their outer extended positions thereofand also upon displacement thereof in the opposite angular directioninto another active position being engageable with a plurality of saidcontacts to move the same into their outer extended positions, and givestructure provided by said splice box for positively determining theposition of said casing with respect that such track component uponinsertion of said casing section thereinto and thereby enablinginterconnection of said contacts with the respective conductors of suchtrack component by appropriate movement of said selector structure inone or the other of such opposite angular directions.

10. The splice box of claim 9 in which each of said contacts is anelongated spring component having an end portion thereof extendinglongitudinally in substantially unsupported relation and biased towardthe inner retracted position thereof, and in which said selectorstructure is abuttably engageable with the end portion of each contactto displace the same laterally into its outer extended position andthereby effect engagement thereof with a conductor of such trackcomponent.

11. The splice box of claim 9 in which said selector structure has camsurfaces engageable with a certain two of said contacts to move the sameinto their outer extended positions upon displacement of said selectorstructure in either of said opposite angular directions into one or theother of said active positions and is equipped with a cam portionengageable with the third of said contacts only when displaced in one ofsaid opposite angular directions into the active position associatedtherewith to move said third contact into its outer extended positionconcurrently with movement of the aforesaid two contacts.

1. A splice box or the like for use in a power distribution system having a track component provided with a longitudinally extending chamber therealong equipped with a conductor assembly that includes a plurality of conductors insulating one from the others, comprising a casing having a section thereof insertable into such chamber, a pair of contacts mounted within said casing and movable with respect thereto between inner retracted positions and outer extended positions for respective engagement with such conductors following insertion of said casing section into such chamber, selector structure adjustably carried by said casing for movement with respect thereto and being engageable with said contacts to displace the same selectively from their retracted positions into their extended positions, guide structure carried by said casing and cooperative with such track component to positively determine the position of said casing with respect thereto upon insertion of said casing section thereinto and thereby enable interconnection of said contacts with the respective conductors of such track component by appropriate movement of said selector structure, and an additional contact mounted within said casiNg and being movable with respect thereto between an inner retracted position and an outer extended position for engagement with one such conductor following insertion of said casing section into the chamber of such track component, said selector structure being movable in one direction to effect displacement of said additional contact into the outer extended position thereof concurrently with corresponding displacements of the aforesaid pair of contacts into their outer extended positions and being movable in an opposite direction to displace the aforesaid pair of contacts outwardly into their extended positions without so displacing said additional contact into its outer extended position, said casing being provided with an end portion larger in at least one transverse dimension than said casing section and being abuttable with an end of such track component to limit the extent of insertion of said casing section into the chamber thereof, said guide structure extending along said casing section in spacedapart overlying relation therewith for slidable insertion into such track component.
 2. The splice box of claim 1 in which each of said contacts is an elongated component having an end portion thereof extending longitudinally in substantially unsupported relation, and in which said selector structure is engageable with the end portion of each contact to displace the same laterally into its outer extended position and thereby effect engagement thereof with a conductor of such track component.
 3. The splice box of claim 2 in which said selector structure has an offset portion engageable with said additional contact to displace the same laterally into its outer extended position when said selector structure is moved in one direction and ineffective to displace it into such outer extended position when said selector structure is moved in the opposite direction.
 4. A splice box or the like for use in a power distribution system having a track component provided with a longitudinally extending chamber therealong equipped with a conductor assembly that includes a plurality of conductors insulating one from the others, comprising a casing having a section thereof insertable into such chamber, a pair of contacts mounted within said casing and movable with respect thereto between inner retracted positions and outer extended positions for respective engagement with such conductors following insertion of said casing section into such chamber, selector structure adjustably carried by said casing for movement with respect thereto and being engageable with said contacts to displace the same selectively from their retracted positions into their extended positions, and guide structure carried by said casing and cooperative with such track component to positively determine the position of said casing with respect thereto upon insertion of said casing section thereinto and thereby enable interconnection of said contacts with the respective conductors of such track component by appropriate movement of said selector structure, said guide structure extending along said casing section in spaced-apart overlying relation therewith for slidable insertion into such track component.
 5. The splice box of claim 4 and further comprising an additional contact mounted within said casing and being movable with respect thereto between an inner retracted position and an outer extended position for engagement with one such conductor following insertion of said casing section into the chamber of such track component, and in which said selector structure is movable in one direction to effect displacement of said additional contact into the outer extended position thereof concurrently with corresponding displacements of the aforesaid pair of contacts into their outer extended positions and is movable in an opposite direction to displace the aforesaid pair of contacts outwardly into their extended positions without so displacing said additional contact into its outer extended position.
 6. A splice box or the like for use in a power distribution system having a track component provided with a longitudinally extending chamber therealong equipped with a conductor assembly that includes a plurality of conductors insulating one from the others, comprising a casing having a section thereof insertable into such chamber, a pair of contacts mounted within said casing and movable with respect thereto between inner retracted positions and outer extended positions for respective engagement with such conductors following insertion of said casing section into such chamber, selector structure adjustably carried by said casing for movement with respect thereto and being engageable with said contacts to displace the same selectively from their retracted positions into their extended positions, guide structure carried by said casing and cooperative with such track component to positively determine the position of said casing with respect thereto upon insertion of said casing section thereinto and thereby enable interconnection of said contacts with the respective conductors of such track component by appropriate movement of said selector structure, said casing having an end portion from which said section thereof extends and a connector strap for securing two such splice boxes in longitudinal disposition with said end portions thereof in substantial abutment and said casing sections projecting therefrom in opposite longitudinal directions, said casing being equipped with means for securing said connector strap thereto.
 7. The splice box of claim 6 in which said casing is equipped with a removable cover, and in which said securing means are provided thereby.
 8. The splice box of claim 7 in which said casing and removable cover are provided with insulating barriers separating said contacts thereat to insulate the same from each other.
 9. A splice box or the like for use in a power distribution system having a track component provided with a longitudinally extending chamber therealong equipped with a conductor assembly that includes a plurality of conductors insulating one from the others, comprising a casing having a section thereof insertable into such chamber, at least three contacts mounted within said casing and being movable with respect thereto between inner retracted positions and outer extended positions for respective engagement with such conductors following insertion of said casing section into such chamber, three-position selector structure pivotally carried by said casing for selective displacements with respect thereto in opposite angular directions from an intermediate neutral position into one or another of two active positions, said selector structure upon displacement thereof in one angular direction into one active position being engageable with a plurality of said contacts to move the same into their outer extended positions thereof and also upon displacement thereof in the opposite angular direction into another active position being engageable with a plurality of said contacts to move the same into their outer extended positions, and give structure provided by said splice box for positively determining the position of said casing with respect that such track component upon insertion of said casing section thereinto and thereby enabling interconnection of said contacts with the respective conductors of such track component by appropriate movement of said selector structure in one or the other of such opposite angular directions.
 10. The splice box of claim 9 in which each of said contacts is an elongated spring component having an end portion thereof extending longitudinally in substantially unsupported relation and biased toward the inner retracted position thereof, and in which said selector structure is abuttably engageable with the end portion of each contact to displace the same laterally into its outer extended position and thereby effect engagement thereof with a conductor of such track component.
 11. The splice box of claim 9 in Which said selector structure has cam surfaces engageable with a certain two of said contacts to move the same into their outer extended positions upon displacement of said selector structure in either of said opposite angular directions into one or the other of said active positions and is equipped with a cam portion engageable with the third of said contacts only when displaced in one of said opposite angular directions into the active position associated therewith to move said third contact into its outer extended position concurrently with movement of the aforesaid two contacts. 